Nikolai Berdyaev

According to Marko Marković, Berdyaev "was an ardent man, rebellious to all authority, an independent and "negative" spirit. He could assert himself only in negation and could not hear any assertion without immediately negating it, to such an extent that he would even be able to contradict himself and to attack people who shared his own prior opinions". According to Marina Makienko, Anna Panamaryova, and Andrey Gurban, Berdyaev's works are "emotional, controversial, bombastic, affective and dogmatic". They summarise that, according to Berdyaev, "man unites two worlds – the world of the divine and the natural world.... Through the freedom and creativity the two natures must unite... To overcome the dualism of existence is possible only through creativity.

David Bonner Richardson described Berdyaev's philosophy as Christian existentialism and personalism. Other authors, such as political theologian Tsoncho Tsonchev, interpret Berdyaev as "communitarian personalist" and Slavophile. According to Tsonchev, Berdyaev's philosophical thought rests on four "pillars": freedom, creativity, person, and communion.

One of the central themes of Berdyaev's work was philosophy of love. At first he systematically developed his theory of love in a special article published in the journal Pereval (Russian: Перевал) in 1907. Then he gave gender issues a notable place in his book The Meaning of the Creative Act (1916). According to him, 1) erotic energy is an eternal source of creativity, 2) eroticism is linked to beauty, and eros means search for the beautiful.

He also published works about Russian history and the Russian national character. In particular, he wrote about Russian nationalism:

The Russian people did not achieve their ancient dream of Moscow, the Third Rome. The ecclesiastical schism of the seventeenth century revealed that the muscovite tsardom is not the third Rome. The messianic idea of the Russian people assumed either an apocalyptic form or a revolutionary; and then there occurred an amazing event in the destiny of the Russian people. Instead of the Third Rome in Russia, the Third International was achieved, and many of the features of the Third Rome pass over to the Third International. The Third International is also a Holy Empire, and it also is founded on an Orthodox faith. The Third International is not international, but a Russian national idea.

Though sometimes quoted as a Christian anarchist for his emphasis on theology and critique of statist and Marxist socialism, Berdyaev did not self-identify as such and differentiated himself from Leo Tolstoy.

Nikolai Berdyaev's work is also featured in the dedication of Aldous Huxley's 1932 novel "Brave New World".